Emergency power supply



FIG. 1 is a perspective view of an emergency power supply showing my new design;

FIG. 2 is another perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.

The broken lines in the drawings depict portions of the emergency power supply that form no part of the claimed design. 

CLAIM The ornamental design for an emergency power supply, as shown and described. 